Machines for bending segmental annular plate or sheet into conical frustom

ABSTRACT

A machine for bending a segmental annular sheet or plate into a conical frustom comprises a pair of upper and lower feed rolls arranged in parallel with a gap therebetween sufficient to grip and feed the segmental annular sheet or plate therethrough, and a pair of bending rolls obliquely disposed adjacent to and on opposite sides of the paired feed rollers. In order to carry out taper bending quickly and easily, the paired feed rolls are provided around their lesser diameter end portions with highspeed feed rings driven independently of the paired feed rolls and capable of positively feeding the longer arc part of the segmental annular sheet or plate at a speed greater than that of the shorter arc part fed by the paired feed rolls.

United States Patent 1191 Tsuru 1 Oct. 30, 1973 [54] MACHINES FOR BENDING SEGMENT AL 49,045 7/1865 Valentine et al. 72/169 ANNULAR PLATE 0 SHEET INTO. 1,735,243 11/1929 Hahnemann 72/169 CONICAL FRUSTOM Primary Examiner-Milton S. Mehr [75] Inventor: Kokichi Tsuru, Mitagawa-machi, Atmmey john McGlew et al Japan [73] Assignee: Kabushiki Kaisha Tsuru Tekkosho, [57] ABSTRACT M'tagawa'mach" Kanzak"gun A machine for bending a segmental annular sheet or Japan plate into a conical frustom comprises a pair of upper [22] Filed: Apr. 20, 1972 and lower feed rolls arranged in parallel with a gap therebetween sufficient to grip and feed the segmental [2]] Appl 246,010 annular sheet or plate therethrough, and a pair of bending rolls obliquely disposed adjacent to and on 52 US. (:1. 72/169, 72/175 pp Sides of the paired feed rollers- Order to 51 1111. C1 B2ld 9/10 carry out taper bending q y and easily, the Paired [58] Field of Search 72/169, 170, 175, feed rolls are Provided around their lesser diameter 72 1 7 end portions with high-speed feed rings driven independently of the paired feed rolls and capable of posi- [56] Refer n Cited tively feeding the longer are part of the segmental an- UNITED STATES PATENTS nular sheet or plate at a speed greater than that of the 2,696,242 12 1954 Knost 72 175 x Shorter are part fed by the feed 3,623,349 11/1971 Hausler 72/169 9 Claims, 5 Drawing Figures 1 2O 15 A 5 B 13 l IO 2 l8 9 2 l l6 6 7 I5 l f B I 4 1 8 e 2 I2 2 PMENTEU URI 30 I973 SHEET 10F 2 FIG.

MACHINES FOR BENDING SEGMENTAL 'ANNULAR PLATE OR SHEET INTO CONICAL FRUSTOM BACKGROUND OF THE INVENTION This invention relates to a machine for bending a segmental annular sheet or plate into a conical frustom by forcing it through a pair of rotatable and tiltable bending rolls arranged on opposite sides of a pair of feeding rolls.

In forming the conical frustom by such bending machine, it is essential that the segmental annular sheet or plate is so fed by the feed rolls that the longer arc part thereof passes thereacross at a speed greater than that of the shorter are part, otherwise the conical frustom can not be provided. In order to differentiate the speeds of the longer and shorter are parts, it has been heretofore practised to decelerate the speed of the shorter are part by applying a braking action thereon. However, this results in various disadvantages. For example, anefficiency in the bending work is affected adversely.

SUMMARY OF THE INVENTION It is therefore a general object of this invention to provide a bending machine of the type described which facilitates the prompt bending of a segmental annular sheet orplate into a conical frustom.

In accordance with the invention, a bending machine is provided comprising a pair of low-speed feed rolls arranged substantially in parallel relative to each other with a gap therebetween sufficient to feed the segmental annular sheet or plate therethrough, a pair of tiltable and rotatable bending rolls disposed adjacent to and on opposite sides of the paired low-speed feed rolls, and a pair of high-speed feed rings provided for rotation around the ends of the feed rolls respectively. The highspeed feed rings have an outer diameter greater than that of the low-speed feed rolls and can be driven at a circumferential speed greater than that of the lowspeed feed rolls independently of the latter. When it is desired to provide the bending, the end of the longer are part of the sheet or plate is forced between the paired high-speed feed rings whereas the end of the shorter are part thereof is interposed between the ends of the paired low-speed feed rolls remote from the high-speed feed rings, so that the longer are part can be fed at the greater speed than that of the shorter are part, thus effectively forming the segmental annular sheet or plate into the conical frustom with ease.

Other ojbects, features, and advantages of the invention will become apparent from the subsequent description taken in conjunction with the accompanying drawings which form a part of this specification. pg,3

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a conically bending machine of the invention, with bending rolls partly omitted for the purpose of illustration;

FIG. 2 is a fragmental enlarged view showing the essential parts of the invention in section;

FIG. 3 is a cross sectional view through the bending and feeding rolls, taken on the line A A of FIG. 1, with the segmental annular sheet or plate attached thereto;

FIG. 4 is a cross-sectional view, corresponding to FIG. 3, taken on the line B B of FIG. 1; and

FIG. 5 is a fragmental plan view showing mainly the bending rolls, with parts broken away for the purpose of illustration.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, on a bed I mounted are a pair of spaced upright columns 2 and 2' for rotatably supporting opposite ends of a pair of upper and lower low-speed feed rolls 3 and 4, and opposite ends of a pair of bending rolls 10 arranged on the opposite sides of the paired low-speed feed rolls. The opposite ends of each of the bending rolls 10 can be moved separately along the associated columns 2 and 2' by operating a handle 12 connected to a screw threaded rod 11 engaging the associated end of the bending roll as in the conventional bending machines of the type described. The upper feed roll 3 can be also moved along the columns 2 and 2 by operating a handle 14 connected to a screw threaded rod 13 engaging the associated end of the upper feed roll 3.

In the embodiment, the lower feed roll '4 and the paired bending rolls 10 are adapted to be driven at a suitable speed, through universal joint shafts l5 and a change speed gearing (not shown) housed in a gear box 16, by a prime mover l7 operatively connected to the change speed gearing. When a complete 360 curvature has been formed so that it encircles the upper feed roll, at least one of the bearings of the latter is necessary to be released so that one end of the upper feed roll may be raised and the piece in the form of a conical frustom removed. For the purpose, means is provided for tilting the column 2 clockwise in FIG. 1, thereby separating the right hand end of the upper feed roll 3 from the column 2. The tilting means comprises a connecting shaft 18 fixedly connected at one end to the column 2 and engaging at the other end with a screw threaded rod 19 screw thread fitted to an upright column. As will be apparent, by operating a handle 20 fixed to the rod 19, the other end of the shaft 18 is lowered by the screw threaded rod 19 and the column 2 tilted clockwise.

The essential parts of the invention are best shown, on an enlarged scale, in FIG. 2.

According to the present invention, in order to provide a differentiation between the feeding speeds of the longer and shorter are parts of the segmental annular sheet or plate, which speed differentiation is necessary for providing the conical frustom, the upper and lower feed rolls 3 and 4 are provided respectively around their lesser diameter end portions with a pair of highspeed feed members 6 in the form of a ring.

To facilitate the high-speed feeding of the longer are part of the sheet or plate, the ring 6 is preferably knurled as shown in FIG. 1 and the ring 6. has an outer diameter greater than that of the associated feed roll. The ring 6 is mounted for rotation through a metal lining 5 acting as a bearing therefor. To rotate the rings 6 independently of the low-speed feed rolls 3 and 4, the rings 6 are provided at their end with gears 7 meshing together, one of which is in driving engagement with a gear 9 driven by a driving means 8 mounted on the bed 1. The driving means 8 may be a speed variable geared motor. As the driving means 8 is variable in speed, the rotational speed of the high-speed feed rings 6 can be readily controlled according to the difference in length between the shorter and longer are parts of the segmental annular sheet or plate.

The gear 7 may be an integral part of the associated ring 6 and the upper gear 7 not engaging the gear 9 may be omitted as the case may be.

Furthermore, it is preferable to provide, as best shown in FIG. 5, each of the bending rolls 10 with a knurled ring 6' in a similar manner to facilitate the differential feeding of the segmental annular sheet or plate. The knurled ring 6' has an outer diameter greater than that of the associated bending roll and is mounted, through a metal lining on the same side as the ring 6 provided on the low-speed feed roll. As the ring 6 is knurled and has the greater diameter than that of the bending roll 10, it is rotated faster than the bending roll by friction, assisting in the higher-speed feeding of the longer are part of the segmental annular sheet or plate.

In operation, the sheet or plate a (see FIGS. 2-4) is inserted into the gap between the paired low-speed feed rolls 3 and 4 with its longer are part 21 being gripped between the paired high-speed feed rings 6 and with its shorter arc part 22 being gripped between the ends of the paired low-speed feed rolls 3 and 4 remote from the paired high-speed feed rings 6. Thereafter, the bending rolls 10 are suitably tilted by rotating the handle 12 to cause the shorter arc part 22 to be deflected more upward than the longer are part 21, whereby the longer and shorter are parts 21 and 22 are bent into the complete curvature to form the conical frustom.

In passing through the gap between the low-speed feed rolls 3 and 4, the longer arc part 21 is positively fed faster than the shorter are part 22 by the high-speed feed rings 6 driven independently of the low-speed feed rolls 3 and 4, with the attendant advantage that the bending of the segmental annular sheet or plate into the conical frustom can be effected promptly, exactly, and easily.

While the invention has been illustrated and described with reference to a single preferred embodiment thereof, it is to be understood that various changes in the details of construction, and the arrangement and combination of parts may be made without departing from the spirit and scope of the invention.

What I claim is:

l. A machine for bending a segmental annular sheet or plate member into a conical frustom, comprising a pair of low-speed feed rolls mounted for rotation with a gap therebetween sufficient to grip and feed said sheet member therethrough, a pair of tiltable and rotatable bending rolls arranged substantially in parallel to each other and on opposite sides of said low-speed feed rolls, a low-speed driving means for driving at least one of said paired low-speed feed rolls at a predetermined circumferential speed to feed said sheet member, a pair of high-speed feed members in the form of a ring mounted around lesser diameter end portions of said paired low-speed feed rolls for rotation independently of said paired low-speed feed rolls, each of said high speed feed members having a greater outer diameter than that of the associated low-speed feed roll, and a high-speed driving means for positively driving at least one of said high'speed feed members at a circumferential speed greater than said predetermined circumferential speed of said low-speed feed rolls attained by said low-speed driving means.

2. A machine as claimed in claim 1, wherein said high-speed feed members are knurled to ensure said sheet member to be firmly gripped thereby.

3. A machine as claimed in claim 1, wherein said paired low-speed feed rolls and said paired high-speed feed members are arranged horizontally with one above the other respectively.

4. A machine as claimed in claim 3, wherein the rotation of said high-speed driving means is transmitted through a gear train to the lower one of said paired high-speed feed members, said gear train including a driving gear connected to said high-speed driving means, and a first driven gear meshing with said driving gear and mounted around the lesser diameter end portion of the lower one of said low-speed feed rolls in a manner as rotating in unison with the lower one of said high-speed feed members.

5. A machine as claimed in claim 4, wherein said gear train further includes a second driven gear meshing with said first driven gear and mounted around the lesser diameter end portion of the upper one of said low-speed feed rolls in a manner as rotating in unison with the upper one of said high-speed feed members.

6. A machine as claimed in claim 5, wherein said first and second driven gears are integral parts of said upper and lower high-speed feed members.

7. A machine as claimed in claim 1, wherein said high-speed driving means is a speed variable geared motor. 1 Y

8. A machine as claimed in claim 1, wherein each of said bending rolls has a ring mounted for rotation around its lesser diameter end portion on the same side as said paired high-speed feed members, said ring having a greater diameter than that of the associated bending roll.

9. A machine as claimed in claim 8, wherein said rings on the bending rolls are knurled. 

1. A machine for bending a segmental annular sheet or plate member into a conical frustom, comprising a pair of low-speed feed rolls mounted for rotation with a gap therebetween sufficient to grip and feed said sheet member therethrough, a pair of tiltable and rotatable bending rolls arranged substantially in parallel to each other and on opposite sides of said low-speed feed rolls, a low-speed driving means for driving at least one of said paired low-speed feed rolls at a predetermined circumferential speed to feed said sheet member, a pair of high-speed feed members in the form of a ring mounted around lesser diameter end portions of said paired low-speed feed rolls for rotation independently of said paired low-speed feed rolls, each of said high-speed feed members having a greater outer diameter than that of the associated low-speed feed roll, and a high-speed driving means for positively driving at least one of said high-speed feed members at a circumferential speed greater than said predetermined circumferential speed of said low-speed feed rolls attained by said low-speed driving means.
 2. A machine as claimed in claim 1, wherein said high-speed feed members are knurled to ensure said sheet member to be firmly gripped thereby.
 3. A machine as claimed in claim 1, wherein said paired low-speed feed rolls and said paired high-speed feed members are arranged horizontally with one above the other respectively.
 4. A machine as claimed in claim 3, wherein the rotation of said high-speed driving means is transmitted through a gear train to the lower one of said paired high-speed feed members, said gear train including a driving gear connected to said high-speed driving means, and a first driven gear meshing with said driving gear and mounted around the lesser diameter end portion of the lower one of said low-speed feed rolls in a manner as rotating in unison with the lower one of said high-speed feed members.
 5. A machine as clAimed in claim 4, wherein said gear train further includes a second driven gear meshing with said first driven gear and mounted around the lesser diameter end portion of the upper one of said low-speed feed rolls in a manner as rotating in unison with the upper one of said high-speed feed members.
 6. A machine as claimed in claim 5, wherein said first and second driven gears are integral parts of said upper and lower high-speed feed members.
 7. A machine as claimed in claim 1, wherein said high-speed driving means is a speed variable geared motor.
 8. A machine as claimed in claim 1, wherein each of said bending rolls has a ring mounted for rotation around its lesser diameter end portion on the same side as said paired high-speed feed members, said ring having a greater diameter than that of the associated bending roll.
 9. A machine as claimed in claim 8, wherein said rings on the bending rolls are knurled. 